Working up of hydroformylation or carbonylation reaction mixtures

Abstract

Reaction mixtures which are obtained on hydroformylation or carbonylation of olefinically unsaturated compounds and which contain dissolved non-volatile complex compounds of metals of group VIII of the periodic table are worked up by a method wherein the products, after distillative removal of low-boiling constituents alone, or of these constituents plus a part of the high-boiling residue, or a part of the high-boiling residue after distillative removal of the desired products, are or is extracted with carbon dioxide, a C 2 -C 4 -paraffin, a C 2 -C 4 -olefin or a normally gaseous halohydrocarbon at above the critical temperature and above the critical pressure of these (extractant) compounds.

We claim: 
     
       1. A process for working up a reaction mixture formed in producing aldehydes and/or alcohols or acids and/or esters by the hydroformylation or carbonylation of olefins in the presence of non-volatile catalytic complex compounds of metals of group VIII of the periodic table and wherein the desired aldehydes and/or alcohols or acids and/or esters are recovered from the reaction mixture leaving behind high-boiling residue in which said non-volatile catalytic compounds are dissolved, which process comprises: contacting the reaction mixture containing non-volatile catalytic compounds dissolved in high-boiling residue with an extractant compound selected from the group consisting of carbon dioxide, a C 2  -C 4  -paraffin, a C 2  -C 4  olefin or a normally gaseous halohydrocarbon at a temperature above the critical temperature of the extractant compound and at a pressure above the critical pressure of the extractant compound to separate high-boiling residue from the non-volatile catalyst, and thereafter returning the catalyst to the reaction mixture. 
     
     
       2. The process of claim 1, wherein the non-volatile catalytic complex is a compound of cobalt or rhodium. 
     
     
       3. The process of claim 2 wherein the process temperature is from 5° to 50° C. above the critical temperature of the extractant compound and the process pressure is from 40 to 200 bar above the critical pressure of the extractant compound. 
     
     
       4. The process of claim 2 wherein the low-boiling constituents of the reaction mixture and the desired products have been removed before the reaction mixture is contacted with the extractant compound. 
     
     
       5. The process of claim 2, wherein from 20 to 80% by weight of the high-boiling residue is separated from the non-volatile catalyst by extraction.